When he set up the complex deal that funneled money to Nicaraguan guerrillas (contras) from secret arms sales to Iran, Lt. Col. Oliver L. North did more than touch off a political crisis in Ronald Reagan's presidency. North also set in motion a chain of events that could lead to fundamental changes in the National Security Council (NSC), the embattled agency for which he worked, and thus reshape the decision-making process in foreign affairs.

As a formal decision-making body—composed of the president, the vice president and the secretaries of state and defense—the NSC has played a dominant role in determining U.S. diplomatic and military strategy only occasionally during its 40-year history. Instead, its staff, headed by the national security adviser, has evolved into an apparatus with which the president seeks to carry out his own vision of how the United States should relate to the rest of the world. The chief goals of the NSC have been to advise the president and coordinate the policies of the State and Defense departments and other agencies involved in foreign relations.

The extent to which the staff strayed from that mission will be examined by a three-member Special Review Board appointed by Reagan Nov. 26 and headed by former Texas Republican Sen. John G. Tower. In addition, two special congressional committees and an independent counsel, Lawrence E. Walsh, have been appointed to investigate the Iran-contra affair. The investigations are looking at possible violations of a variety of laws, including those that barred aid to the contras and the sale of arms to nations that support terrorism, and required disclosure to Congress of arms sales and covert actions.